Recently, as an example of the augmented reality technology (hereinafter, referred to as an AR technology), virtual digital information (virtual object) is displayed to be superimposed on real space information such as a real-space image. In addition, the virtual object is shared between a plurality of devices, so that the virtual object is preferably treated as an object in the real space.
In order to superimpose the virtual digital information on the real space information, the virtual space needs to be recognized by analyzing a three-dimensional space structure. For example, in Patent Literature 1, there is disclosed a technology where a plurality of users share a virtual space to allow the position in each of the user's real space and the position in the virtual space to correspond to each other so as for the users to recognize and contact each other in the virtual space.